FILM FOR HEAT SEAL AND SEPARATION AND RECOVERY METHOD FOR THE SAME

• Main Authors: YOSHIDA KENTARO, ISHIUCHI SATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 09.02.2023
• Subjects: ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS,e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES,DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; CONVEYING; HANDLING THIN OR FILAMENTARY MATERIAL; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PACKAGES; PACKAGING ELEMENTS; PACKING; PERFORMING OPERATIONS; STORING; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

To provide a film for heat seal which has a heat fusion layer soluble in an aqueous solution, and is excellent in separation recovery property and heat seal strength under high humidity, and a separation and recovery method for the film for heat seal.SOLUTION: A film for heat seal is provided in which a heat fusion layer (X) composed of a water-soluble resin composition (S) is provided on one outermost layer, and a water-insoluble base material layer (Z) including at least one selected from the group consisting of a thermoplastic resin, paper and a metallic foil is provided on the other outermost layer, wherein an equilibrium moisture content at a temperature of 23°C and relative humidity of 50% of the water-soluble resin composition (S) is 3 mass% or more and 10 mass% or less, the water-soluble resin composition (S) includes a hydroxyl group-containing resin (A) having a melting point of 220°C or lower as a main component, and the water-soluble resin composition (S) includes 100 ppm or more and 2,000 ppm or less of alkali metal ions (B).SELECTED DRAWING: None 【課題】熱融着層が水溶液可溶性であり、分離回収性及び高湿度下ヒートシール強度に優れるヒートシール用フィルム及びその分離回収方法を提供する。【解決手段】水溶性樹脂組成物（Ｓ）からなる熱融着層（Ｘ）を一方の最外層に備え、熱可塑性樹脂、紙及び金属箔からなる群より選ばれる少なくとも１種を含む非水溶性の基材層（Ｚ）を他方の最外層に備え、水溶性樹脂組成物（Ｓ）の温度２３℃、相対湿度５０％における平衡水分率が３質量％以上１０質量％以下であり、水溶性樹脂組成物（Ｓ）が融点２２０℃以下の水酸基含有樹脂（Ａ）を主成分として含み、水溶性樹脂組成物（Ｓ）がアルカリ金属イオン（Ｂ）を１００ｐｐｍ以上２０００ｐｐｍ以下含む、ヒートシール用フィルム。【選択図】なし